Enoki (Flammulina velutipes, golden needle mushroom, winter mushroom) is one of the most popular edible mushrooms worldwide. Its natural habitat is in the northern hemisphere, preferring cooler climates. Even very cold. It is able to grow even in winter when temperatures drop to zero. Hence one of its names, winter mushroom. Enoki is a saprophyte that grows attached to tree trunks or stumps from which it obtains nutrients for its growth. Enoki typically grows in clumps, so it is easy to collect. There are two forms of Enoki, but they have the same composition. Since there is a high demand for Enoki, the mushroom is grown commercially in nurseries. Here it is grown in the cold and dark. Enoki grown in this way is bright, white, has longer legs and small caps. Enoki can be bought in this form in shops. However, if Enoki is grown in the wild and there is contact with light. It acquires a honey-brown colour, the cap is closed at first, then opens and is slightly arched. Slightly sticky on the surface. Its diameter varies from 2-8 mm. The foot is thin and slightly 'hairy', giving the impression of being velvety.

Enoki is widely used in the kitchen. It is suitable for various types of sauté or ragout, it can be fried, added to omelettes, soup. It can be combined with almost all raw materials - vegetables, meat, legumes, pasta, potatoes... Up to 300,000 tonnes of it are produced annually.

If you go to the Enoki forest, beware of possible confusion with mushrooms, which can harm your health. One such mushroom is the conifer cap, which is highly poisonous. It is also wood-boring and grows in clusters.

As with everything, allergic reactions have been reported to Enoki, which may be due to the presence of flammutoxin, which has a negative effect on the heart. However, the flammutoxin is broken down, neutralised when the mushroom is cooked. Its toxicity to the heart only becomes apparent at high doses, and it takes only a small amount to cause an allergic reaction. However, there is no need to worry about e.g. mushroom supplements. The risk is mainly when eating fresh mushrooms.

Enoki has also been known for centuries in Asia, where it has been used as a medicine by the local people. Mainly in China, as part of traditional Chinese medicine, but it is also popular and used for treatment in Japan and Korea. The written sources in which Enoki is mentioned date back to 900 AD, i.e. the Han Dynasty. The text contains information not only on the use but also on the cultivation of the mushroom. Yes, Enoki was already cultivated 'artificially' at that time. It is described what is the most suitable substrate for growing the mushroom, what kind of moisture it needs, etc.

Its inclusion in the taxonomy took a relatively long time, only occurring in the 19th century. M. A. Curtis (1808-1872) named Enoki as Agaricus velutipes, i.e. classified Enoki as a mushroom. This changed, however, when the German mycologist Rolf Singer reclassified it in 1947 and then also renamed it Flammulina velutipes, a name the fungus still bears today.

In modern history, Dr Tetsuro Ikekawa, who was an epidemiologist at the National Cancer Center Research Institute in Tokyo, was interested in the effects of Enoki. In mapping the incidence of cancer between 1972 and 1986, he found that the Nagano area had the lowest incidence of cancer nationwide. Enoki growers are abundant in this area and, of course, they also consume the mushroom regularly. Ikekawa logically concluded that this epidemiological anomaly in cancer incidence was caused by the mushroom. His study sparked further research into the mushroom and the search for both its exact composition and effects.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5141589/

Composition of Enoki

Sugar components

Enoki, like other mushrooms, is very rich in carbohydrates. Especially polysaccharides, which are composed of many monosaccharides that are linked together to form a large molecule. It is therefore clear that there are many types of polysaccharides, which have different sizes, different compositions and therefore different effects. The best known polysaccharides are beta glucans. There are both beta and, to a lesser extent, alpha glucans in enoki. In addition to the polysaccharides that are absorbed from the gut, Enoki also contains non-absorbable polysaccharides, i.e. coarse fibre, chitin. Through massive research on Enoki, a large number of polysaccharides have been extracted and many have shown significant biological effects and have also been given their names, FVP1, FVP2, SFR1, PA3DE, PA5DE. FVP1, for example, has a molecular weight of 54.78 kDa and is composed of glucose (70.41%), mannose (7.74%) and galactose (16.38%). It induces cytokine secretion by immune cells and neutralizes free radicals. Another important polysaccharide is PK25, which contains xylose, mannose, glucose... FVP60 is composed of fucose, mannose, glucose and galactose, in the ratios 1.16 : 0.82 : 1.00 : 3.08.

However, there are many more carbohydrates found in Enoki, including free monosaccharides.

Proteins and amino acids

Although mushrooms are classified in the plant kingdom, they also contain large amounts of protein, which is unusual for plants. Enoki contains large amounts of amino acids and protein. It also contains amino acids that our bodies cannot make and therefore rely on food to supply them, these are essential amino acids. Glutamic acid has the highest representation in Enoki, followed by alanine, glycine, lysine, methionine, valine, phenylalanine, threonine, etc. Amino acids are not only the building blocks of proteins, but also give the mushroom its taste and aroma. The amino acids that have sulphur in them are mainly used.

The most famous proteins in Enoki are undoubtedly those named FIPs (fungal immunomodulatory proteins). The name completely corresponds to their effects, i.e. they are immunomodulatory proteins.

Other proteins are proteins whose activity results in inactivation of ribosomes (RIPs), which leads to the arrest of protein synthesis. This is because ribosomes read information from mRNA, which is a transcript of DNA, and carries information about the protein to be made. Examples of these proteins include flammin, flammulin and velin. However, these enzymes can also fight viruses because their proteins are made by the host cell. Viruses carry DNA/RNA with information for protein synthesis, but cannot synthesize their own proteins. They use the ribosomes of the infected cell to do this. If the ribosomes are blocked, e.g. by velin, they do not synthesize viral proteins.

We mentioned flammutoxin in the previous text. This is cytolysin, a cytolytic protein that disrupts cells until they undergo lysis ("disintegration"). Flammutoxin is mainly directed against red blood cells. But not all of them. Flammutoxin mainly affects the red blood cells of rabbits, guinea pigs, humans, mice, cats and dogs. The red blood cells of sheep, oxen, goats and horses, on the other hand, survive contact with flammutoxin. The toxin creates tiny holes in the cell membrane, causing a disruption of the membrane. This causes potassium to leak out of the cell, the cell literally swells and 'bursts'. Flammutoxin also has a negative effect on the heart muscle. It blocks calcium channels, thereby altering the activity of the heart cells, which must contract to maintain heart function.

However, a very high dose of flammutoxin would be required for such an effect and there is no risk from normal consumption.

Enoki also contains a large number of enzymes that enable it to break down wood and extract nutrients from it. One of these is lactase, for example. As well as polysaccharides, there may already be several types. In Enoki there are also glucogenases, glucosidases, xylosidases or peroxidases.

Furthermore, there are also enzymes that break bonds in proteins, peptides and modify/degrade amino acids, e.g. prolyl endopeptidase, FvpP, or asparaginase and glutaminase.

The high content of active enzymes gives Enoki the ability to degrade not only wood but also many toxic substances in the environment.

Fats (lipids) and fatty acids

Fatty acids and lipids can also be found in Enoki. Both saturated and unsaturated fatty acids are represented, with the unsaturated (healthful) ones making up 80%.

Enoki also contains unsaturated essential fatty acids, similar to amino acids, which are those that the body cannot synthesise and must take in through food. These are, for example, cis-linoleic acid. In Enoki, they make up 40.87% of all fatty acids.

Of the saturated fatty acids, it contains e.g. caprylic, palmitic, stearic or arachidonic acid. Unsaturated fatty acids are represented by cis-oleic acid, the aforementioned cis-linoleic acid, eicosapentaenoic acid and others.

Overall, in the dry matter of mushrooms, saturated fatty acids constitute about 19 %, monounsaturated fatty acids about 19,5 % and polyunsaturated fatty acids (PUFA) more than 60 %.

Lipid particles also include ceramides and glycosiceramides, which are also found in Enoki.

Vitamins and minerals

Enoki is not lacking in vitamins, mineral and trace elements. Among the vitamins, we can mention B vitamins, mainly thiamine, pantothenic acid, riboflavin, niacin. There is also vitamin D, E and beta carotene. In Enoki there is also lycopene, which also belongs to carotenoids.

The mineral composition also depends on the environment in which the mushroom grows. In general, however, sodium, potassium, calcium, phosphorus, iron, copper, zinc, selenium... are always present in the mushroom.

Phenols and terpenes

Enoki also contains phenols and terpenes. These are substances that have antioxidant effects.

The ingredients found are for example: elegalic acid, p-coumaric, caffeic and ferulic acid, pyrogallol, quercetin, xanthoxylin, 6-gingerol, cyclocurcumin, dendrocandin 1, osmatnthusid H, forsythosid D, moracin G, etc.

There are also terpene compounds in Enoki, among which the sesquiterpene flammulinol A dominates, which is similar to other terpenes flammulinolides A-G. Furthermore, there are, for example, flamvelutpenoids A-D, enokipodins A-D.

Flavonoids derived from Enoki include, for example, arbutin, epicatechin, fibrin, apigenin, campferol and formononetin.

https://www.sciencedirect.com/science/article/pii/S2314853518302518

Sterols

We have already mentioned one sterol above, as vitamin D2 is ergosterol. Other sterol compounds, often with literally frighteningly long names, include. cerevistosterol, ergost-8(14)-ene-3β-ol, 22,23-dihydroergosterol, 5α, 8α-epidioxy-(22E, 24R)-23-methylergosta-6, 22-diene-3β-ol, 3β, 5α, 9α-trihydroxy-(22E, 24R)-23-methylergosta-7, 22-dien-6-one, 3β, 5α, 9α-trihydroxy-(24S)-ergost-7-en-6-one, 3β, 5α, 9α, 14α-tetrahydroxy-(22E, 24R)-ergosta-7, 22-diene-6-one, (22E, 24R)-ergosta-7, 22-diene-3β, 5α, 6α, 9α-tetrol, 5α, 9α-epidioxy-3β-hydroxy-(22E, 24R)-ergosta-7, 22-diene-6-one, 5α, 9α-epidioxy-3β-hydroxy-(24S)-ergosta-7-en-6-one and 5α, 6α-epoxy-(22E, 24R)-ergosta-8, 22-diene-3β, 7β, 14α-triol.